Grinding wheel



C. KLINGSPOR GRINDING WHEEL May 2, 1961 Filed Jan. 15, 1959 451. (Am/as P1218 Un e S ate at n 07 GRINDING WHEEL Carl Klingspor, Waldstrasse 13a, Siegen, Westphalia, 7 Germany Filed Jan. 13, 1959, Ser. No. 786,469 Claims priority, application Austria Jan. 18, 1958 6 Claims. (ch 51-206) widthof the abrasive member for machining. For instance, a grinding wheel having a width of 40-60 mm. machines only with one fourth or one fifth of said width. This means that the work performed by the grinding 'wheel is done by a fraction of the periphery of, the

wheel, namely, by that portion which is in front when viewed in the feeding direction. Under these circumstances it is advisableto avoid grinding wheels having an uneconomical width and to use narrow grinding wheels separated by free spaces.

This does not'enable the actual utilization of the entire It is known to cause several grinding wheels held spaced by insert rings to act on the workpiece at the same time. Abrasive segments are also known which are combined to form one or several abrasive rings acting on the workpiece. Y I

These. proposals are unsatisfactory because several wheels each of which functions satisfactory in itself will work satisfactorily when combined only if their diameters are appropriately selected. As even the slightest differences in composition, which are due to the manufacture of the wheels, cause a differential wear of the grinding wheels, it is not or hardly-possible" in practice to maintain this relation of the diameters. For this reason the usefulness of such sets of grinding wheels is highly problematical- It has also been proposed to align several spaced grinding wheels on a shaft and to set the Wheels at an angle to the shaft like wobble plates, having a more or less elliptical periphery, depending on their inclination. As a result, the working surface of the abrasive member has an effective width which is a fraction of the working width required for the abrasive member. The rotation of the abrasive member causes its grinding face to travel axially along the workpiece. This construction is unsatisfactory because the use of elliptical abrasive members is unsatisfactory in itself and because such abrasive members when combined have rotary balance only if their major and minor axes, respectively, lie exactly in common planes. This requires an exact alignment of the grinding wheels on the spindle, which alignment is difficult to achieve and maintain.

The present invention proceeds on a different course. It provides a rotary abrasive member for use like agrinding wheel, which member is composed of a plurality of axially aligned, hard components and the working face of which has an acting width which is a fraction of the working width required for the abrasive member, the lateral boundary faces of the components being inclined with respect to the axis of rotation of the abrasive memher so that a rotation of the abrasive member will cause 5 2,982,060 latented May 2, 19 6} the abrading face thereof to travel axially over the workpiece, and is characterizedin that the components complement to form a helical body, the axial cross-section of which decreases fromthe inside towards the outside. Each component preferably forms only. a sector-shaped part of the'helical body i.e. the peripheral length of each component is less than 360 degrees, and adjacent components form staggered joints. 7

Thus, this does not concern an arrangement of several separate grinding wheels one beside the other, which wheels cover the entire working width only as a result ofa feed movement'impartedto them, but a functional unit, which provides the working width byia special configuration of the working face of the abrasive member although this does not preclude the additional use of a feed movement. Whereas the components are also inclined with respect to the axis they are not confined by ellipses but have circular outer boundary edges.

It will be appreciated that an abrasive member according to the invention having a working surface in the form of a helical strip will produce an uninterrupted ground surface and grinding marks cannot occur. Using' discs having each a width of 3-20 mm. it thus possible to obtain a multiple-turn helical member havingra grinding width of 6-60 mm. and more without feed movement. If an inclined grinding ,wheel element has at its periphery an acting width of, e.g., 4 mm., the inclination or helical configuration maybe such as to give that element a working width of about 5-l0 mm. Thus, the performance of'the wheel element is greatly increased beyond its actual grinding width whereas the generation of heat and thepower requireme'ntare reduced owing to the reduced thickness. 7 This disc can also be cooled more satisfactorily.

It'has been found suitable for the components assembled to form the helical body to have a high strength and a substantial elasticity. In this connection it is sufficient, however, to use those compositions known for abrasive members which have a relatively high strength and elasticity owing' to. the use of high-grade bonding materials and may be improved by an admixture of fiber materials. A person skilled in the art will be aware of such compositions for abrasive members and they need not be discussed here more fully. Besides, the crosssectional shape of the components according to the invention also contributes to the strength thereof, the rotating mass decreasing from the inside to the outside according to a linear or non-linear function. The reduction in cross-section from the center to the periphery should not be less than would result from a taper of 1:10.

The invention is illustrated in the accompanying drawing, in which Fig. l is an end view showing an abrasive component for an abrasive member according to the invention.

Fig. 2 is a sectional view taken on line II-II of Fig. 1.

Fig. 3 is a partly sectional view showing an abrasive member according to the invention, mounted on a grinding spindle.

Fig, 4 shows as a detail of the construction of Fig. 3, the joint between adjacent abrasive components.

Near the rim 2 of its center hole the sector shaped helical abrasive component 1 has in its helical side faces axially extending concentric flanges 3, which serve for effectively anchoring a series of such components in the complementary circular recesses of carrying rings 4, Fig.

3. These carrying rings consist of ring sectors which complement to form a helical body carried by the shaft 5 and having the same lead as the helical abrasive member formed by the components 1. The helical member consisting .of the ring sectors 4 is non-displaceably gripped "august;

1"" -1.M."3 F1; ,lPY. ines 5 ?1 @b r qeflans 7 a 11 ha t which has screw-threaded extensions 8 for this purpose.

It is apparent from Fig.4 that the joint between one s t qn nt 1a 491 th ,n x .l ma .gfi t-t i -,4 i ha 911 Planyi w w he j int betwee tw adi een qm o entsz i shl ial bq n rvs am gb of each componenthas a continuous oifsetsothat in- .terengaging steps .are formed. at the radialboundary face of adjacent components. Th'eaxial spacing of the components may also be such that the beginning of one component is axially spaced from the end of the preceding component. This will result in an abrasive member formed like winding stairs. It will be understood that these are only details of constructionand other fixations n s su a ma qbs d d-, r .The abrasive member having according to the invenform of "a helical body (helical surface or winding stairs) has a grinding performance similar to that of a plurality of narrow grinding wheels and enables the s ame or an increased removal. of material with an abrasive memberhavi'ng a much lower weight; it is free of the above-mentioneddisadvantages of a plurality of circular or elliptical individual discs aligned parallel to each other on a shaft. The abrasive member according to the invention has also 3 the advantage that components of different grain size and even of different diameter may .be carried on a single shaft. The (helical) space between the components ensures an effective discharge of the abrasive dust. Each component does not only grind at its end but also with its side owing to the helical movement of the same.

:What is claimedis;

A rotary grinding member, eornprising ashaft having an axis; a plurality of abrasive components mounted ,on said shaft, eachone of said componentshavingtwo liadially extending sidefaces spacedly facingcorresponding side faces of another component in. an. axial direction, .a. grinding. face, connecting said side fa'ces, the grinding .faces of said components defining a surface of revolution .about said axis, and two radially extending bounding l'faces, each of said, bo,unding faces connecting the two v"side facesof said onecomponent andextending radially from said grinding face thereof, said two bounding faces grinding face extending helically between said bounding faces, each bounding face of said one component being positioned for abutting engagement with a corresponding bounding face of an adjacent component, whereby the grinding faces of the twg adja cept members form a joint, said grinding faces at said joint having respective portions which overlap in axial and in a circumferential direction; and fastening means for securing said components to saidshaft.

2. A grinding member as set forth in claim 1, said two bounding "faces being offset angularly by an angle of more than and substantially less than 360.

3. A grindingmember as set forth in claim 2, wherein at least one, of said sideffaces is formed with an axial projection of arcuate shape about said axis, and said fastening means includes a ring member interposed between said one side face and the facingside face of another component, said ring member being formed with a recess matingly engaging said projection, and means for securing said ring member on said shaft.

4. A grinding member as set forth in claim 1, said two side faces of each component converging axially in a radially outward direction. v

5. A grinding member as set forth in claim 1, wherein each boundary face has a radially extending offset mat- ,ingly engaging a corresponding offset on the corresponding boundary faceof the adjacent member, wherebythe joint formed .by the grinding faces of the two adjacent members has a step-like shape in said surface of revolua 6. A grinding member as set forth in claim 1, wherein said surface of revolution is a cylinder.

References Citedin the file or this patent UNITED STATES PATENTS 

